KOMATSU 421-33-11440 Seal Ring (Brake Piston Seal)
Product Overview
The KOMATSU 421-33-11440 Seal Ring is a Genuine Komatsu OEM brake piston seal designed for use in the machine’s wet disc brake system. Installed within the brake cylinder assembly, the seal ring maintains hydraulic pressure around the brake piston, preventing hydraulic oil leakage while ensuring consistent brake engagement and reliable braking performance. Komatsu officially lists this component as a Seal within the Wet Disc Brake category.
Manufactured to Komatsu’s stringent OEM specifications, the 421-33-11440 Seal Ring is engineered to withstand hydraulic pressure, continuous braking cycles, vibration, and harsh operating environments. Designed as a direct OEM replacement, it restores the original sealing performance of the brake assembly and helps maintain safe machine operation.
Key Features
- Genuine Komatsu OEM Brake Piston Seal Ring
- Part Number: 421-33-11440
- Designed for wet disc brake assemblies
- Maintains hydraulic sealing around the brake piston
- Prevents hydraulic oil leakage
- Supports consistent brake performance
- Manufactured to Komatsu OEM specifications
- Direct OEM replacement
- Resistant to hydraulic oil, pressure, and temperature variations
- Suitable for demanding construction, mining, quarrying, and haulage applications
Technical Specifications
| Specification | Details |
|---|---|
| Part Number | 421-33-11440 |
| Product Type | Brake Piston Seal Ring |
| Category | Wet Disc Brake |
| Function | Seals the brake piston to maintain hydraulic pressure and prevent fluid leakage |
| Installation | Direct OEM replacement |
| Brand | Komatsu |
Note: Komatsu has not publicly published OEM specifications such as seal material, hardness (durometer), dimensions, pressure rating, or operating temperature range for the 421-33-11440 Seal Ring. Always verify the correct part using the machine serial number and the official Komatsu Parts Catalog before ordering.
Application Information
The KOMATSU 421-33-11440 Seal Ring is a critical sealing component within the wet disc brake piston assembly. It creates a hydraulic seal between the brake piston and cylinder, allowing hydraulic pressure to actuate the brake while preventing internal fluid leakage. Proper sealing is essential for maintaining braking efficiency, reducing hydraulic pressure loss, and protecting the brake assembly from contamination.
Manufactured to Komatsu OEM standards, the seal ring is designed to withstand:
- Continuous hydraulic pressure
- Repeated brake engagement cycles
- Hydraulic oil exposure
- High operating temperatures
- Vibration and shock loads
- Harsh construction, mining, and quarry environments
Regular inspection and replacement of worn brake piston seals help maintain braking performance, improve operator safety, and reduce the risk of brake system failures.
Compatible Komatsu Equipment
The KOMATSU 421-33-11440 Seal Ring is used in the wet disc brake assemblies of various Komatsu machines, including:
Wheel Loaders
- WA400
- WA420
- WA450
- WA470
- WA500
Rigid Dump Trucks
- HD325
- HD405
Articulated Dump Trucks
- HM250
- HM300
- HM350
- HM400
Compatibility varies depending on the machine model, axle configuration, brake assembly, and serial number. Always verify compatibility using the machine’s Product Identification Number (PIN), Machine Serial Number, and existing part number before ordering.
Additional Compatibility Information
The 421-33-11440 Seal Ring is a configuration-specific brake system component. Before installation, verify:
- Machine model
- Machine Serial Number
- Product Identification Number (PIN)
- Axle and brake assembly configuration
- Existing seal part number
- Brake cylinder configuration
Any modifications to the original machine configuration may affect compatibility. Verification through the official Komatsu Parts Catalog or an authorized Komatsu dealer is recommended before installation.
Benefits
Installing a genuine KOMATSU 421-33-11440 Seal Ring helps:
- Restore proper hydraulic sealing of the brake piston
- Prevent hydraulic oil leakage
- Maintain consistent braking performance
- Improve brake system reliability
- Protect internal brake components from contamination
- Reduce maintenance-related downtime
- Preserve original OEM brake system performance
- Deliver OEM-quality fit, durability, and long-lasting sealing performance in demanding heavy-duty applications.
- Brand New / Genuine Surplus Komatsu Part
- Professionally inspected before dispatch
- Ready for immediate shipment (subject to stock availability)
Worldwide Shipping
We maintain ready-to-ship inventory for many Caterpillar parts. Orders are dispatched the same business day upon receipt of bank payment, with fast worldwide delivery available via DHL and FedEx.
Disclaimer: We are an independent supplier of genuine surplus Komatsu parts. We are not an authorized Komatsu distributor or dealer. All trademarks, product names, and model numbers are used solely for identification purposes.
